mod.rkt

#lang racket/base

(module m racket/base
  (provide (struct-out exn:fail)
           (rename-out [exn-message            exn:fail-message]
                       [exn-continuation-marks exn:fail-continuation-marks])))

(require 'm)

(define e (exn:fail "foo" (current-continuation-marks)))
(exn-message e)      ;still works
(exn:fail-message e) ;also works